Find a level spot in the garage or driveway and place some kind of wheel chocks behind the rear wheels to keep it from rolling away.
Jack the machine up using the center of the chassis in the front. Be sure to place the jack on the flattest part of the chassis up front but far enough back that it doesn't slide back off once in the air. You just want the front wheels barely off the ground just so they spin freely.
Put both hands on each wheel in the 9 and 3 o'clock positions. Gently push the wheel to the front and back simulating turning the steering. You'll be looking for looseness in the steering. If one wheel moves slightly before the other, you could have worn steering tie rod ends.
Placing your hand at the 12 o'clock position on the wheel while then pushing in at the top will reveal loose wheel bearings. If there is any movement to the slightest pressure from the 12 o'clock position, you might have a wheel bearing issue.
The last test is for the ball joints that hold the upper and lower control arms to the wheel hub or steering knuckle. Pulling out, then pushing in on the bottom of the wheel while observing the Upper and lower A-Arms will reveal loose ball joints.